Not new but had no idea where to put this, we have a 2500hd pickup that gets TERRIBLE gas mileage, on average 10 to 12 city and no more than 14 on the highway, and the truck just seems so gutless, no power, expessially when towing, were just not sure where to go. Has new air filter and plugs and wires.

Mods feel free to move to appropriate section.

 

You try to change the fuel filter and also might want to unbolt the cat and see if its getting cloged.

 

The fuel filter has been changed, guess I never thought about cats, ill see if I can get them undone tomorrow. Any other suggestions?

 

honestly you wont get much better mpg than that in that truck. my buddy's dad bought one in 02 brand new and has put like 250k on it, got about that gas mileage since it was new. the power issue might be a problem though, those trucks have quite a bit of torque.

 

I could live with the mileage if this thing had some more giddy up and go, my bosses 5.3 suburban feels a good deal quicker. I was thinking with our truck having the 4.10's in it that it should have no problem roasting the tires, but 90% of the time it cant get out of its own way. Theres no codes in it current or history, im just not sure what to do really.

 

I've had a 2500 with the 6.0 and that's what my mileage was. 15 MPG was nearly impossible to reach.

 

the HDs gas mileage is awful bc of the bigger motor (6.0) and the towing rear end gears. they kill your mileage. i believe the suspensions are heavier as well. so you have more displacement, numerically higher rear end, and more weight.....death to gas mileage

 

I agree on the mileage issue. I have a "FORMULA 1 TON" cargo van 6.0, 4L80 etc 1 ton heavy stuff. The best HWY MPG I ever got was 14. The upside was it gets the same MPG with 1500 lbs of **** in it and it rides a lot smoother.

Good luck on finding the power problem.

 

the 4l80E has bad gearing imo. That'll make the 6.0 feel sluggish. My boss has a 6.0 in his 2500 and the truck is slow. I've come to the conclusion it's all in the trannys gearing. The 4l60e has a much lower 1st gear to get the truck moving. Only advantage with the 80 is it's OD is .75, rather than the 60's .70

 

my fathers 03 silverado 2500, 6L with 4.10s in the back got pretty consistent 15-16mpg in highway driving (not major highway...but 60-70mph stuff).

 

My '01 Silverado 1500 HD crew cab (LQ4 6.0L) gets 15 MPG on the highway. Around town I don't check it much, but think it is around 12 MPG.

 

how accurate is the insturment display? in my silverado ss my avg mpg is 17.2 mixed with both city and hwy.. 4.10's, awd, volant, fast 33#inj. and a tune.

 

Nope that sounds about right on the mileage. As for power, I don't think you'll "roast the tires" They weren't made to light. Mine doesn't turn them very easily. Now as for being gutless when towing I don't know what your talking about. I tow our siding trailer at work and it seems to pull just fine. I'm talking a 3 or 4 ton trailer. Mine has the 4.10 gears too.

On a side note I can keep up with a buddy of mines stock type-s, I can beat a buddies stock four door neon , and I also held dead even with a 95 5.0 Stang. So personally I was quite happy with the truck. I no these are all slow cars but I was driving a full sized long bed truck.

 

a tune couldget a little better fuel milage with the truck and wake up the motor a good bite. the hd 6.0 is the most restictive motor when tuned from the factory. I got about 1 mpg and a lot more power out of mine from myself tuning it and I'm not good at it yet. Some of the better tuners are getting 3=4 mpg out of a tune in these trucks.